| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a novolak phenolic resin at a production cost which can be reduced not only because it can produce a novolak phenolic resin having controlled contents of phenolic monomers and phenolic dimers and a controlled polydispersity index in a high yield but also because it includes an efficient washing step. SOLUTION: The method comprises the 1st step of subjecting a phenol and an aldehyde to a heterogeneous system reaction in the presence of a phosphoric acid and the 2nd step of separating the reaction mixture into a water layer and an organic layer after the 1st step, removing the water layer, and bringing the organic layer into contact with an ion exchange resin. COPYRIGHT: (C)2006,JPO&NCIPI
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